A kit you say - that sounds like a formidable task for a serial scratch builder - and I must confess that the last plastic kit I built was an Airfix kit when I was 14!! so YES this will be a challenge for me.

I purchased two unmade HELJAN - CONCOR Steam Locomotive Roundhouse Kits B802 and 803 from the bring and buy members' tables at the NMRA BR Derby Convention in October 2015.

Last edited by PeterBowen on Wed Sep 07, 2016 3:21 pm, edited 3 times in total.

I have always been familiar with doing a lot of research and studying photos, drawing plans and trying to imagine what the structure will look like before attempting to start fabricating parts, but this has all been done and when I opened the box, there it is all of the parts and a very simple plan.

Open the box...

Take a look at the parts...

Nice end wall detail - the brickwork is very nice.

The real challenge will be trying to make the fantastic detail look less plastic...!!!

While the HELJAN Roundhouse kit is based on the Roundhouse at Northumberland, PA studying the photos reveals that the manufacturer has taken some artistic licence to make a kit that is representative of the style of what a brick built roundhouse structure might have looked like.

Also I find prototype photos help in modelling to understand the structure inside and out.

I found the picture below taken in May 1968, not too long before all of the engines were sent to Strasburg. This is the kind of authentic setting I like to see locomotives displayed in. Roundhouse and coal dock were destroyed about 1986 or so, sadly.

Demolition of the roundhouse happened in the spring and summer of 1987.

There was some serious lobbying to get the Railroad Museum of Pennsylvania established in part at this very roundhouse, for many of the reasons: still-extant water tanks and coaling tower, auxiliary buildings, etc. There was also some minor quizzical thoughts about the feasibility of relocating Steamtown to the site at one point in the "we've got to get out of Vermont" phase; I'm reasonably certain Pennsy fanatic Don Ball was quite aware of the possibilities of the Northumberland site during his tenure as director. Unfortunately, here's the brutal reality:

1) the roundhouse, and the yard by which it was surrounded, were in a flood plain--one that takes a bit of doing to flood, but it is there. I believe I've seen photos of the turntable pit being pumped out post-flooding.

2) The roundhouse, at the time (and the site still to this day) was surrounded by active railroad trackage and yards. The nearest road access is via approximately 1.5 miles or more of private road through a railroad yard. (If I remember correctly, I had to cross one main line, six main yard tracks, and two or three sidings to get to the roundhouse, *after* PC and Conrail had made major reductions in trackage.) If this museum had been opened here in the 1970s, it would have mandated its own access road and overpasses, infrastructure costs that might have dwarfed even those of restoring a decrepit roundhouse or those of the Steamtown NHS. And for what? You still don't have a track on which to operate. (Employees actually made short-cut use of "the Rat Hole", a long underground sidewalk constructed as a bridge spanning the water of a wide underground culvert system, with access stairs poking up at the east end beside a street in a neighbourhood where many of them lived, various points in the yard, and at the yard office and roundhouse.)

3) Northumberland itself was, and still is, very badly situated for auto traffic and tourist demands. At the present time there is planning underway to construct a major four-lane limited-access highway to the west to bypass, among other places, Northumberland, Sunbury, and Shamokin Dam, theoretically bridging the Susquehanna just to the north of Northumberland Yard. The reason, among others: Traffic through Northumberland is horribly jammed from a combination of local and through traffic on two-lane streets.

As I mentioned previously, I wanted to show how to transform some great detail of the brickwork from a plastic look to a more realistic “weathered” brick look.

In my clinic on “weathering” that I presented at the NMRA Convention in Derby in October I tried to show real life examples of weathering and how everyday structures are affected.

One important thing to remember is that most natural things have muted colours and everything looks quite grey, there are no really bright colours. So when it comes to painting a plastic wall of bricks you could expect to see muted tones and a random brick colours.

OK on with the paint…!!!

I like to use Vallejo acrylic paints because they are water based and can be applied straight out of the bottle and mixed with water to create thin washes of colour.

I often use an airbrush to apply paint because I like the control and fine subtle application of the colour in layers, but I know a lot of people don’t have access to an airbrush so I will be using a good quality brush to demonstrate how to apply washes of colour.

This type of brush is capable of applying lots of water and paint plus very fine detail.

I like to mix paint with water in a plastic lid and can create “puddles” of paint in various consistencies.

The first coat of paint applied full strength is Vallejo – Red Leather (a good representation of red brick colour) applied with the brush mentioned above. Just slop it on working the paint into the mortar lines as well. This gives a good base for further washes of paint.

Now that the first coat of undiluted paint has been allowed to dry thoroughly overnight, it is time to start the next step of applying diluted washes of paint on to the brick surface.

This method involves applying thin washes which are essentially transparent over each other to slowly build up a very realistic (in my opinion) looking brick surface.

A wash is a diluted mix of paint that is applied to a wet surface. When the diluted paint hits the wet surface something magical happens . . . the paint spreads outwards – it is quite magical and it will find its way into all the mortar lines and cracks and spread across the brick surface.

I am now going to apply a wash of Vallejo No. 305 Light Rubber – a medium grey colour and ideal as a first wash application.

Wet the surface with plain ordinary tap water. Some people have suggested adding detergent to reduce the surface tension of the water but I don’t bother with that. Plain old tap water works quite well, but make sure the surface is wet all over.

Next apply the diluted mix of Vallejo No. 305 Light Rubber paint – don’t be concerned if it looks like a mess, it will dry very diluted and produce a very subtle effect.

After everything has dried overnight, the result does not look as good as it did when it was wet with paint. But be patient, this is a process of laying down thin washes of colour to build up a three dimensional look.

We are trying to make the lovely plastic cast detail look like real bricks and the way to do this is with many layers of paint in different shades.

So here is the starting point:

Continue on with washes of grey and mix some Vallejo No. 883 Silver Grey into the mix - don't use it full strength, remember to keep the washes very thin with lots of water.

The mortar lines are starting to stand out and the bricks have some further dimension to them.

IMPORTANT leave to dry for at least 6 hours between washes, this is to allow the paint to dry. If you are not careful you can actually wash the previous layer(s) off completely. Sometimes I apply "hair spray" yes ordinary hairspray acts like a fixative and seals the paint, but at this stage I would not recommend doing that.

The next photo shows how the brick effect is starting to look.

The next step is to mix up some darker brick colours using the original red brick colour that we started with Vallejo No.70818 Red Leather + Vallejo No. 305 Light Rubber + Vallejo No. 71042 Cam Black Brown

Be very careful not to make the mix look to muddy, the mix is very small quantities of paint and lots of water to make a thin wash that is applied with the same paint brush mentioned above, to individual bricks.

The fine bristles on the brush will produce a very fine point.

Note the detail of random bricks painted just here and there… and a trick that I learned many years ago by applying a darker wash under a window sill to represent a shadow…!!

A closeup of the brick wall to show the detail that can be achieved with just paint…!!

The completed wall for comparison.

Later on we will apply further weathering using chalks and powders to enhance the effect even further.

Closer inspection of the kit components and the lack of any instructions is like looking at a jigsaw puzzle and trying to imagine what goes where and how.

I thought I should be looking at how the inside floor goes together as this will determine the foundation shape and angles etc.

One concern that I have is how far back does the structure sit form the centre of the turntable?

The floor is made up of a series of angled sections each the width of one stall:

When laid out next to each other they look like this:

I have laid lengths of stripwood from the approximate centreline of each stall to determine the point of intersection and thus the centre of the turntable.

I plan on eventually using Walthers Conerstone 130ft Turntable which is 17.92 inches (455.17mm) in diameter.

Using the NMRA App (available from the Apple iTunes Store and Google Play) and the Scale Converter it is very quick and easy to see results.

Each Roundhouse Stall is 15.25 inches from front to back:

The distance from the back wall of the Roundhouse to the centre point of the turntable (the intersection of the centrelines) is 30.25 inches.

The distance from the front wall of the Roundhouse to the centre point of the turntable is 15 inches.

After removing the central sprue and keeping the spacer sprues in place for added strength while cementing together I quickly realised that keeping the entire floor flat was going to be a challenge in itself.

Being used to scratch building everything and thinking about the structure and how it goes together this kit leaves a lot to be desired. The one thing that bothers me is the apparent weakness in the floor and the big gaps between the angles stall sections.

While the flooring sections provide the basis and foundation for the structure I am wondering about what the finished Roundhouse would look like without these clunky sections – could I do without them?